U.S. patent number 9,803,374 [Application Number 14/973,179] was granted by the patent office on 2017-10-31 for mechanical locking system for floor panels.
This patent grant is currently assigned to CERALOC INNOVATION AB. The grantee listed for this patent is CERALOC INNOVATION AB. Invention is credited to Darko Pervan.
United States Patent |
9,803,374 |
Pervan |
October 31, 2017 |
Mechanical locking system for floor panels
Abstract
Floor panels (1, 1') are shown, which are provided with a
mechanical locking system that may be locked with a vertical
displacement of a first panel against a second panel. The locking
system includes a flexible strip (6) that during locking bends
upwardly or downwardly. The locking system includes a first (7a)
and a second (7b) joint edge section with different locking
functions. One section provides a horizontal locking and another
section provides a vertical locking.
Inventors: |
Pervan; Darko (Viken,
SE) |
Applicant: |
Name |
City |
State |
Country |
Type |
CERALOC INNOVATION AB |
Viken |
N/A |
SE |
|
|
Assignee: |
CERALOC INNOVATION AB (Viken,
SE)
|
Family
ID: |
56151127 |
Appl.
No.: |
14/973,179 |
Filed: |
December 17, 2015 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20160201336 A1 |
Jul 14, 2016 |
|
Foreign Application Priority Data
|
|
|
|
|
Dec 22, 2014 [SE] |
|
|
1451632 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E04F
15/02038 (20130101); B26D 3/065 (20130101); E04C
2/40 (20130101); E04F 15/107 (20130101); E04F
15/102 (20130101); E04F 2201/0161 (20130101); E04F
2201/043 (20130101); E04F 2201/0176 (20130101); E04F
2201/0146 (20130101); E04F 2201/042 (20130101) |
Current International
Class: |
E04F
15/02 (20060101); E04F 15/10 (20060101); E04C
2/40 (20060101); B26D 3/06 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
10 2004 001 363 |
|
Aug 2005 |
|
DE |
|
10 2005 024 336 |
|
Nov 2006 |
|
DE |
|
20 2007 018 935 |
|
Oct 2009 |
|
DE |
|
10 2009 048 050 |
|
Jan 2011 |
|
DE |
|
1 350 904 |
|
Oct 2003 |
|
EP |
|
1 350 904 |
|
Oct 2003 |
|
EP |
|
1 420 125 |
|
May 2004 |
|
EP |
|
1 437 457 |
|
Jul 2004 |
|
EP |
|
1 640 530 |
|
Mar 2006 |
|
EP |
|
1 980 683 |
|
Oct 2008 |
|
EP |
|
2 327 502 |
|
Oct 2009 |
|
ES |
|
2 327 502 |
|
Mar 2013 |
|
ES |
|
WO 00/20705 |
|
Apr 2000 |
|
WO |
|
WO 00/47841 |
|
Aug 2000 |
|
WO |
|
WO 01/02669 |
|
Jan 2001 |
|
WO |
|
WO 01/51732 |
|
Jul 2001 |
|
WO |
|
WO 01/51733 |
|
Jul 2001 |
|
WO |
|
WO 01/75247 |
|
Oct 2001 |
|
WO |
|
WO 01/77461 |
|
Oct 2001 |
|
WO |
|
WO 01/88306 |
|
Nov 2001 |
|
WO |
|
WO 03/012224 |
|
Feb 2003 |
|
WO |
|
WO 03/025307 |
|
Mar 2003 |
|
WO |
|
WO 03/038210 |
|
May 2003 |
|
WO |
|
WO 03/089736 |
|
Oct 2003 |
|
WO |
|
WO 2005/003489 |
|
Jan 2005 |
|
WO |
|
WO 2006/043893 |
|
Apr 2006 |
|
WO |
|
WO 2007/015669 |
|
Feb 2007 |
|
WO |
|
WO 2007/015669 |
|
Feb 2007 |
|
WO |
|
WO 2007/141605 |
|
Dec 2007 |
|
WO |
|
WO 2008/004960 |
|
Jan 2008 |
|
WO |
|
WO 2008/004960 |
|
Jan 2008 |
|
WO |
|
WO 2008/116623 |
|
Oct 2008 |
|
WO |
|
WO 2009/033623 |
|
Mar 2009 |
|
WO |
|
WO 2009/116926 |
|
Sep 2009 |
|
WO |
|
WO 2010/086084 |
|
Aug 2010 |
|
WO |
|
WO 2010/100046 |
|
Sep 2010 |
|
WO |
|
WO 2011/001326 |
|
Jan 2011 |
|
WO |
|
WO 2011/038709 |
|
Apr 2011 |
|
WO |
|
WO 2012/084604 |
|
Jun 2012 |
|
WO |
|
WO 2013/191632 |
|
Dec 2013 |
|
WO |
|
Other References
International Search Report and Written Opinion mailed Mar. 31,
2016 in PCT/SE2015/051367, Patent-och registreringsverket,
Stockholm, SE, 18 pages. cited by applicant .
U.S. Appl. No. 14/947,436, Pervan et al. cited by applicant .
U.S. Appl. No. 14/946,066, Boo et al. cited by applicant .
Valinge Innovation AB, Technical Disclosure entitled "Mechanical
locking for floor panels with Vertical Folding," IP.com No.
IPCOM000179246D, Feb. 10, 2009, IP.com PriorArtDatabase, 59 pp.
cited by applicant .
Valinge Innovation AB, Technical Disclosure entitled "Mechanical
locking for floor panels with a flexible bristle tongue," IP.com
No. IPCOM000145262D, Jan. 12, 2007, IP.com PriorArtDatabase, 57
pages. cited by applicant .
**Boo, Christian, et al., U.S. Appl. No. 14/946,066, entitled
"Method for Producing a Mechanical Locking System for Building
Panels," filed in the U.S. Patent and Trademark Office on Nov. 19,
2015. cited by applicant .
Pervan, Darko, et al., U.S. Appl. No. 14/947,436, entitled
"Mechanical Locking of Floor Panels with a Vertical Snap Folding,"
filed in the U.S. Patent and Trademark Office on Nov. 20, 2015.
cited by applicant .
Pervan, Darko, U.S. Appl. No. 15/541,909, entitled "Mechanical
Locking System for Floor Panels," filed in the U.S. Patent and
Trademark Office on Jul. 6, 2017. cited by applicant.
|
Primary Examiner: Stephan; Beth
Attorney, Agent or Firm: Buchanan Ingersoll & Rooney
P.C.
Claims
The invention claimed is:
1. A set of essentially identical floor panels provided with a
mechanical locking system comprising a strip extending horizontally
from a lower part of a first edge and a downwardly open locking
groove formed in an adjacent second edge, wherein the strip
comprises an upwardly protruding locking element configured to
cooperate with the locking groove and to lock the first and the
second edge in a horizontal direction parallel to a main plane of
the floor panels and in a vertical direction perpendicularly to the
horizontal direction, wherein the locking system is configured to
be locked with a vertical displacement of the second edge against
the first edge wherein an outer portion of the strip during an
initial stage of the vertical displacement is configured to bend
upwards towards the second edge and during a final stage of the
vertical displacement is configured to bend downwards towards its
initial unlocked position.
2. The set of essentially identical floor panels as claimed in
claim 1, wherein the mechanical locking system, along the first
edge and the second edge, comprises a first edge section and a
second edge section, wherein a cross section of the locking groove
or a cross section of the locking element varies along the first
edge or the second edge, in a locked position.
3. The set of essentially identical floor panels as claimed in
claim 1, wherein an upper portion of the locking element is
configured to be displaced during locking into a space provided
between an outer groove wall of the locking groove and an inner
surface of the locking element.
4. A set of essentially identical rectangular floor panels each
comprising long edges and a first short edge and a second short
edge, the first short edge and the second short edge being provided
with a mechanical locking system comprising a strip extending
horizontally from a lower part of a first short edge and a
downwardly open locking groove formed in the second short edge, the
strip comprises an upwardly protruding locking element that is
configured to cooperate with the locking groove for locking the
first short edge and the second short edge in a horizontal
direction parallel to a main plane of the panels and in a vertical
direction perpendicularly to the horizontal direction, wherein the
locking element comprises an inner surface, an outer surface and a
top surface, the inner surface being positioned closer to an upper
edge of the first edge than the outer surface, wherein the locking
groove comprises an outer groove wall, an inner groove wall and an
upper groove wall, the outer groove wall is positioned closer to
the upper edge of the second edge than the inner groove wall, the
locking element comprising an upper locking surface and the locking
groove comprising a lower locking surface, wherein the upper
locking surface is spaced vertically above an uppermost surface of
an inner portion of the strip, and wherein in a locked position,
the first short edge and the second short edge comprise a
horizontal plane, a first joint edge section and a second joint
edge section located along the first short edge and the second
short edge, the first edge section is configured such that the
outer groove wall of the locking groove and the inner surface of
the locking element along the horizontal plane are in contact with
each other and lock the first short edge and the second short edge
horizontally and the second edge section is configured such that
along the horizontal plane there is a space between the outer
groove wall of the locking groove and the inner surface of the
locking element, and the upper locking surface of the locking
element and the lower locking surface of the locking groove are
configured to be in contact with each other and to lock the first
short edge and the second short edge vertically.
5. The set of essentially identical rectangular floor panels as
claimed in claim 4, wherein the first edge section is located
closer to a long edge than the second edge section.
6. The set of floor panels as claimed in claim 4, wherein the
locking system is configured to be locked with a vertical
displacement of the second short edge against the first short
edge.
7. The set of floor panels as claimed in claim 6, wherein the
locking system is configured such that a vertical displacement of
the second short edge against the first short edge during an
initial stage of the vertical displacement bends the strip upwards
towards the second edge such that the upper locking surface and
lower locking surface overlap each other.
8. The set of floor panels as claimed in claim 4, wherein the lower
locking surface is essentially horizontal.
9. The set of floor panels as claimed in claim 4, wherein the upper
locking surface is located on the outer surface of the locking
element and the lower locking surface is located on the inner
groove wall of the locking groove.
10. The set of floor panels as claimed in claim 4, wherein a
tangent line to the lower locking surface intersects the outer wall
of the locking groove.
11. A set of essentially identical rectangular floor panels each
comprising long edges and a first short edge and a second short
edge, the first short edge and the second short edge being provided
with a mechanical locking system comprising a strip extending
horizontally from a lower part of a first short edge and a
downwardly open locking groove formed in the second short edge, the
strip comprises an upwardly protruding locking element that is
configured to cooperate with the locking groove for locking the
first short edge and the second short edge in a horizontal
direction parallel to a main plane of the panels and in a vertical
direction perpendicularly to the horizontal direction, wherein the
locking element comprises an inner surface, an outer surface and a
top surface, the inner surface being positioned closer to an upper
edge of the first edge than the outer surface, wherein the locking
groove comprises an outer groove wall, an inner groove wall and an
upper groove wall, the outer groove wall is positioned closer to
the upper edge of the second edge than the inner groove wall, the
locking element comprising an upper locking surface and the locking
groove comprising a lower locking surface, wherein in a locked
position, the first short edge and the second short edge comprise a
horizontal plane, a first joint edge section and a second joint
edge section located along the first short edge and the second
short edge, the first edge section is configured such that the
outer groove wall of the locking groove and the inner surface of
the locking element along the horizontal plane are in contact with
each other and lock the first short edge and the second short edge
horizontally and the second edge section is configured such that
along the horizontal plane there is a space between the outer
groove wall of the locking groove and the inner surface of the
locking element, and the upper locking surface of the locking
element and the lower locking surface of the locking groove are
configured to be in contact with each other and to lock the first
short edge and the second short edge vertically, wherein the
locking system is configured to be locked with a vertical
displacement of the second short edge against the first short edge,
wherein the locking system is configured such that a vertical
displacement of the second short edge against the first short edge
during an initial stage of the vertical displacement bends the
strip upwards towards the second edge such that the upper locking
surface and lower locking surface overlap each other.
12. A set of essentially identical rectangular floor panels each
comprising long edges and a first short edge and a second short
edge, the first short edge and the second short edge being provided
with a mechanical locking system comprising a strip extending
horizontally from a lower part of a first short edge and a
downwardly open locking groove formed in the second short edge, the
strip comprises an upwardly protruding locking element that is
configured to cooperate with the locking groove for locking the
first short edge and the second short edge in a horizontal
direction parallel to a main plane of the panels and in a vertical
direction perpendicularly to the horizontal direction, wherein the
locking element comprises an inner surface, an outer surface and a
top surface, the inner surface being positioned closer to an upper
edge of the first edge than the outer surface, wherein the locking
groove comprises an outer groove wall, an inner groove wall and an
upper groove wall, the outer groove wall is positioned closer to
the upper edge of the second edge than the inner groove wall, the
locking element comprising an upper locking surface and the locking
groove comprising a lower locking surface, wherein in a locked
position, the first short edge and the second short edge comprise a
horizontal plane, a first joint edge section and a second joint
edge section located along the first short edge and the second
short edge, the first edge section is configured such that the
outer groove wall of the locking groove and the inner surface of
the locking element along the horizontal plane are in contact with
each other and lock the first short edge and the second short edge
horizontally and the second edge section is configured such that
along the horizontal plane there is a space between the outer
groove wall of the locking groove and the inner surface of the
locking element, and the upper locking surface of the locking
element and the lower locking surface of the locking groove are
configured to be in contact with each other and to lock the first
short edge and the second short edge vertically, wherein a tangent
line to the lower locking surface intersects the outer wall of the
locking groove.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit of Swedish Application
No. 1451632-2, filed on Dec. 22, 2014. The entire contents of
Swedish Application No. 1451632-2 are hereby incorporated herein by
reference in their entirety.
TECHNICAL FIELD
The disclosure generally relates to the field of mechanical locking
systems for floor panels and building panels. The disclosure
includes panels, floorboards, locking systems and production
methods.
FIELD OF APPLICATION
Embodiments of the present disclosure are particularly suitable for
use in floating floors, which are formed of floor panels having one
or more upper layers comprising, e.g., thermoplastic or
thermosetting material or wood veneer, an intermediate core of
wood-fibre-based material or plastic material and preferably a
lower balancing layer on the rear side of the core. Embodiments of
the disclosure may also be used for joining building panels which
preferably contain a board material for instance wall panels,
ceilings, furniture components and similar.
The following description of prior-art technique, problems of known
systems and objects and features of the disclosure will therefore,
as a non-restrictive example, be aimed above all at this field of
application and in particular at laminate floors comprising an HDF
core and formed as rectangular floor panels with long and shorts
edges intended to be mechanically joined to each other on both long
and short edges.
The long and short edges are mainly used to simplify the
description of the disclosure. The panels may be square. Floor
panels are generally produced with the surface layer pointing
downwards in order to eliminate thickness tolerances of the core
material. Some embodiments and production methods are shown with
the surface pointing upwards in order to simplify the
description.
It should be emphasized that embodiments of the disclosure may be
used in any floor panel on long and/or short edges and it may be
combined with all types of known locking systems on long or short
edges that lock the panels in the horizontal and/or vertical
direction.
BACKGROUND
Relevant parts of this background description are also a part of
embodiments of the disclosed invention.
Several floor panels on the market are installed in a floating
manner with mechanical locking systems formed at the long and short
edges. These systems comprise locking means, which lock the panels
horizontally and vertically. The mechanical locking systems are
usually formed by machining of the core of the panel.
Alternatively, parts of the locking system may be formed of a
separate material, for instance aluminum or plastic material, which
is integrated with the floor panel, i.e. joined with the floor
panel in connection with the manufacture thereof.
Laminate flooring usually comprise a 6-8 mm wood based core, a 0.2
mm thick upper decorative surface layer of laminate and a 0.1 mm
thick lower balancing layer. The laminate surface and the balancing
layer comprise melamine-impregnated paper. The most common core
material is fibreboard with high density and good stability usually
called HDF--High Density Fibreboard. The impregnated surface and
balancing papers are laminated to the core with heat and pressure.
HDF material is hard and has a low flexibility, especially in the
vertical direction perpendicular to the fibre orientation.
Recently a new type of powder based laminate floors has been
introduced. Impregnated paper is replaced with a dry powder mix
comprising wood fibres, melamine particles, aluminum oxide and
pigments. The powder is applied on an HDF core and cured under heat
and pressure. Generally high quality HDF is used with a high resin
content and low water swelling. Advanced decors may be formed with
digital printing. Water based ink is injected into the powder prior
to pressing. Luxury vinyl tile, LVT, flooring with a thickness of
3-6 mm usually comprises a transparent wear layer which may be
coated with an ultraviolet, UV, cured polyurethane, PU, lacquer and
a decorative plastic foil under the transparent foil.
The wear layer and the decorative foil are laminated to one or
several core layers comprising a mix of thermoplastic material and
mineral fillers. The plastic core may be rather soft and flexible
but also rather rigid depending on the filler content.
Wood Plastic Composite floors, generally referred to as WPC floors,
are similar to LVT floors. The core comprises thermosetting
material mixed with wood fibre fillers and is generally stronger
and much more rigid than the mineral based LVT core.
Thermoplastic material such as PVC, PP or PE may be combined with a
mix of wood fibres and mineral particles and this may provide a
wide variety of floor panels with different densities and
flexibilities.
Moisture resistant HDF with a high resin content, and WPC floors,
comprise stronger and more flexible core materials than
conventional HDF based laminate floors and they are generally
produced with a lower thickness.
The above mentioned floor types comprise different core materials
with different flexibility, density and strengths. Locking systems
formed in one piece with the core must be adapted to such different
material properties in order to provide a strong and cost efficient
locking function.
DEFINITION OF SOME TERMS
In the following text, the visible surface of the installed floor
panel is called "front side" or "floor surface", while the opposite
side of the floor panel, facing the sub floor, is called "rear
side". The edge between the front and rear side is called "joint
edge". By "horizontal plane" is meant a plane, which extends
parallel to the front side. Immediately juxtaposed upper parts of
two adjacent joint edges of two joined floor panels together define
a "vertical plane" perpendicular to the horizontal plane.
By "vertical locking" is meant locking parallel to the vertical
plane. By "horizontal locking" is meant locking parallel to the
horizontal plane.
By "up" is meant towards the front side, by "down" towards the rear
side, by "inwardly" mainly horizontally towards an inner and center
part of the panel and by "outwardly" mainly horizontally away from
the center part of the panel.
By "essentially vertical" surface or wall is meant a surface or a
wall that is inclined less than 45 degrees against a vertical
plane.
By "essentially horizontal" surface is meant a surface that is
inclined less than 45 degrees against a horizontal plane.
By locking angle of a surface locking panels in the horizontal
direction is meant the angle of the surface relative a vertical
plane
By locking angle of a surface locking panels in the vertical
direction is meant the angle of the surface relative a horizontal
plane.
A tangent line defines the inclination of a curved wall or
surface.
Related Art and Problems Thereof
For mechanical joining of long edges as well as short edges in the
vertical direction and horizontal direction perpendicular to the
edges several methods may be used.
One of the most used methods is the angle-snap method. The long
edges are installed by angling. Horizontal snapping locks the short
edges. The vertical connection is generally a tongue and a groove
and the horizontal connection is a strip with a locking element in
one edge that cooperates with a locking groove in the adjacent
edge. Locking by snapping is obtained with a flexible strip that
during the initial stage of locking bends downwards and during the
final stage of locking snaps upwards such that the locking element
is inserted into the locking groove.
Similar locking systems may also be produced with a rigid strip and
they are connected with an angling-angling method where both short
and long edges are angled into a locked position.
Advanced so-called "fold down locking systems" with a separate and
flexible tongue on a short edge, generally called "5G systems",
have been introduced where both the long and short edges are locked
with an angling action. A floor panel of this type is presented in
WO 2006/043893. It discloses a floor panel with a short edge
locking system comprising a locking element cooperating with a
locking groove, for horizontal locking, and a flexible bow shaped
so called "banana tongue" cooperating with a tongue groove, for
locking in a vertical direction. The flexible bow shaped tongue is
inserted during production into a displacement groove formed at the
edge.
The tongue bends horizontally along the edge during connection and
makes it possible to install the panels by vertical movement. Long
edges are connected with angling and a vertical scissor movement
caused by the same angling action connects short edges. The
snapping resistance is low and only a low thumb pressure is needed
to press the short edges together during the final stage of the
angling. Such a locking is generally referred to as "vertical
folding".
Similar floor panels are further described in WO 2007/015669. This
invention provides a fold down locking system with an improved
flexible tongue so called "bristle tongue" comprising a straight
outer tongue edge over substantially the whole length of the
tongue. An inner part of the tongue comprises bendable protrusions
extending horizontally along the tongue body.
The above known fold down "5G system" has been very successful and
has captured a major market share of the premium world laminate and
wood flooring markets. The locking is strong and reliable mainly
due to the flexibility and pretension of the separate flexible
tongue that allows a locking with large overlapping essentially
horizontal locking surfaces.
The 5G system and similar system have been less successful in the
low priced market segments. The major reason is that the cost of
the separate tongues and investments in special inserting equipment
that is needed to insert a flexible tongue into a displacement
groove are regarded as rather high in relation to the rather low
price of the floor panels.
Several attempts have been made to provide a fold down locking
system based on a vertical snapping function that may be produced
in one piece with the core in the same way as the one piece
horizontal snap systems. All such attempts have failed especially
when a floor panel comprises an HDF core. This is not a
coincidence.
The failure is based on major problems related to material
properties and production methods. Several of the known locking
systems are based on theoretical geometries and designs that have
not been tested in industrial applications. One of the main reasons
behind the failure is that bending of vertically protruding parts
that are used for the vertical locking of edges is limited to about
50% of the floor thickness or to about 4 mm in an 8 mm thick
laminate floor panel. As comparison it may be mentioned that a
protruding strip for horizontal snapping may extend over a
substantial distance from the upper edge and may protrude 8-10 mm
beyond the upper edge. This may be used to facilitate a downward
bending of the strip and the locking element. Other disadvantages
compared to horizontal snapping are that HDF comprises a fibre
orientation substantially parallel with the floor surface. The
material properties are such that bending of horizontally
protruding parts is easier to accomplish than bending of vertically
protruding parts. Furthermore, lower parts of an HDF board comprise
a higher density and a higher resin content than middle parts and
such properties are also favorable for the horizontal snapping
systems where the strip is formed in the lower part of the
core.
Another circumstance that has supported market introduction of the
horizontal snap systems is the fact that a hammer and a knocking
block may be used to snap the short edges. Fold down systems are so
called tool-less systems and the vertical locking must be
accomplished with hand pressure only.
It would be a major advantage if a one-piece fold down locking
system may be formed with a quality and locking function similar to
the advanced 5G systems.
SUMMARY OF THE DISCLOSURE
An objective of embodiments of the present disclosure is to provide
an improved and more cost efficient fold down locking system for
vertical and horizontal locking of adjacent panels wherein the
locking system is produced in one piece with the core.
A first specific objective is to provide a locking system wherein a
horizontally extending flexible strip may be used to accomplish the
vertical and horizontal locking.
A second specific objective is to provide a locking system with
essentially horizontally extending locking surfaces for the
vertical locking such that a strong locking force may be obtained
in the vertical direction.
A third specific objective is to prevent separation forces between
the edges during locking and to decrease the snapping resistance
such that a tool-less installation may be obtained with low
pressure against the short edges.
A fourth specific objective is to provide a cost efficient method
to form locking elements in a double-end tenor comprising a lower
chain and an upper belt that displace the panel in relation to
several tool stations.
The above objects may be achieved by embodiments of the
disclosure.
According to a first aspect of the disclosure a set of essentially
identical floor panels are provided with a mechanical locking
system comprising a strip extending horizontally from a lower part
of a first edge and a downwardly open locking groove formed in an
adjacent second edge. The strip comprises an upwardly protruding
locking element that is configured to cooperate with the locking
groove and locks the first and the second edge in a horizontal
direction parallel to a main plane of the first and the second
panel and in a vertical direction perpendicularly to the horizontal
direction. The locking system is configured to be locked with a
vertical displacement of the second edge against the first edge
wherein the strip, preferably an outer portion of the strip, during
an initial stage of the vertical displacement is configured to bend
upwards towards the second panel and during a final stage of the
vertical displacement is configured to bend downwards towards its
initial unlocked position.
An upper portion of the locking element may be configured to be
displaced during locking into a space provided between an outer
groove wall of the locking groove and an inner surface of the
locking element. The displacement may be caused by at least one of
a bending, a compression and a twisting of the strip. Optionally,
the upper portion of the locking element may during locking be
further configured to be displaced out from the space.
Bending may comprise rotation and/or a displacement of at least
portions of the strip.
According to one embodiment, the space between the outer groove
wall and the inner surface is a cavity arranged in the inner
surface of the locking element.
According to another embodiment, the space is a cavity arranged in
the outer groove wall of the locking groove. According to yet
another embodiment, the space is partly a cavity arranged in the
inner surface and partly a cavity arranged in the outer groove
wall.
The strip may be configured to bend upwards towards a portion of a
front side of the second panel. The portion may be an outer portion
of the front side.
Optionally, the upward and/or downward bending of the strip may be
combined with at least one of a twisting or a compression of the
strip.
The strip may be configured to bend upwards from the unlocked
position to an end position. Moreover, the strip may be configured
to bend downwards from the end position and at least partly back to
the unlocked position. In a non-limiting example, an outer, lower
portion of the strip is displaced vertically upwards from the
unlocked position to the end position by a first distance and then
is displaced vertically downwards by a second distance, wherein the
second distance is between 10% and 95% of the first distance, e.g.
40% or 50%. In another non-limiting example, the strip bends
completely back to a position corresponding to the unlocked
position so that the second distance is essentially the same as the
first distance.
The first and second panels may comprise a pair of parallel short
edges and a pair of parallel long edges, wherein the long edges are
perpendicular to the short edges.
The first and second edges may be short edges.
The main plane of the first and the second panel may be a
horizontal plane that is essentially parallel with the front side
and/or the rear side of the first and/or the second panel.
By a vertical displacement is meant that the edges of the panels
are displaced against each other at least in a vertical direction.
Optionally, however, the vertical displacement may also be combined
with an angling action. According to one embodiment, the vertical
displacement is a vertical scissor movement caused by the same
angling action that is used to connect the edges of the panels that
are perpendicular to the first and the second edges. For example,
the first and second edges may be short edges and the perpendicular
edges may be long edges.
According to another embodiment, front sides of the first and
second panels are essentially parallel to each other during the
vertical displacement.
The first and the second edge may comprise a first edge section and
a second edge section along the first and the second edge, wherein
a cross section of the locking groove or a cross section of the
locking element varies along the first edge and/or the second edge,
in a locked position.
The cross section of the locking groove or of the locking element
may be a cross section as seen from a side view of the floor
panels.
There may be at least one first edge section and at least one
second edge section.
A shape of the each of the first edge sections may be similar.
Moreover, a shape of each of the second edge sections may be
similar. Alternatively, the shapes of the first edge sections
and/or the second edge sections may vary.
The first edge sections and the second edge sections may be
arranged alternately along the first and the second edge.
There may be a smooth transition between the first and the second
edge sections along the edge. Alternatively, the transition between
the first and the second edge sections along the edge may be
stepped.
According to one embodiment, a first edge section is arranged at a
first and/or a second corner section of the first and second edges.
According to one embodiment, a second edge section is arranged at a
first and/or a second corner section of the first and second edges.
In any of these embodiments, the first and second corner sections
may be arranged adjacent to long edges of the panels.
According to one embodiment, the first and second edges are locked
vertically by means of engagement of an upper locking surface
provided on an outer surface of the locking element and a lower
locking surface provided on an inner groove wall of the locking
groove. In one example, the upper locking surface is provided along
the entire first edge and the lower locking surface is provided
along a part of the second edge. In another example, the upper
locking surface is provided along a part of the first edge and the
lower locking surface is provided along the entire second edge.
During the final stage the locking element may be snapped into the
locked position such that the upper and lower locking surfaces
engage with each other in the locking position. Alternatively, the
locking element may assume the locked position by means of a smooth
displacement upwards and/or downwards such that the upper and lower
locking surfaces engage with each other in the locking position.
For example, the latter may be achieved with a beveled upper and/or
lower locking surface. The strip may also be pressed down by a
lower part of the second panel that presses against an upper part
of the protruding strip and/or the locking element.
According to a second aspect of the disclosure a set of essentially
identical rectangular floor panels each comprising long edges and a
first short edge and a second short edge are provided. The first
short edge and the second short edge are provided with a mechanical
locking system comprising a strip extending horizontally from a
lower part of a first short edge and a downwardly open locking
groove formed in the second short edge. The strip comprises an
upwardly protruding locking element that is configured to cooperate
with the locking groove for locking the first short edge and the
second short edge in a horizontal direction parallel to the main
plane of the panels and in a vertical direction perpendicularly to
the horizontal direction. The locking element comprises an inner
surface, an outer surface and a top surface. The inner surface is
positioned closer to an upper edge of the first panel than the
outer surface. The locking groove comprises an outer groove wall,
an inner groove wall and an upper groove wall, the outer groove
wall being positioned closer to an upper edge of the second panel
than the inner groove wall. The locking element comprises an upper
locking surface and the locking groove comprises a lower locking
surface. In a locked position the first short edge and the second
short edge comprise a first and a second joint edge section located
along the first short edge and the second short edge. The first
edge section is configured such that the outer groove wall of the
locking groove and the inner surface of the locking element along
are in contact with each other along a horizontal plane HP and lock
the first short edge and the second short edge horizontally, and
the second edge section is configured such that along the
horizontal plane HP there is a space between the outer groove wall
of the locking groove and the inner surface of the locking element.
The upper locking surface of the locking element and the lower
locking surface of the locking groove are configured to be in
contact with each other and to lock the first short edge and the
second short edge vertically.
Embodiments of the space between the outer groove wall and the
inner surface are largely analogous to the embodiments described
above in relation to the first aspect, wherein reference is made to
the above. In addition, a length of the space in a length direction
of the short edges may correspond to a length of the second edge
section. Alternatively, the length of the space may be longer than
the length of the second edge section.
The upper locking surface of the locking element and the lower
locking surface of the locking groove may be configured to be in
contact with each other in the second edge section.
The upper locking surface and the lower locking surface form an
overlap in a direction parallel with the main plane of the panels
and perpendicularly to the short edges. Preferably, there is an
overlap only along a portion of the short edges, e.g. in the second
edge section(s). In a first example, the overlap is constant along
the short edges. More specifically, the overlap is constant in the
second edge section(s). In a second example, the overlap varies
along the short edges. The varying overlap may be periodic with a
constant periodicity along the second edge section(s).
According to one embodiment, the upper locking surface extends
along the entire first short edge. In a non-limiting example, there
is no lower locking surface provided in the first edge section.
According to one embodiment, the lower locking surface extends
along the entire second short edge. In a non-limiting example,
there is no upper locking surface provided in the first edge
section.
The upper locking surface or the lower locking surface may extend
along a portion of the first and second short edge,
respectively.
According to a non-limiting embodiment, the upper locking surface
is arranged only in a middle section of the first short edge and
the lower locking surface is provided along the entire second short
edge. Thereby, the upper locking surface is missing from corner
sections of the first short edge, wherein the middle section is a
second edge section and the corner sections are first edge
sections, the middle section being arranged between the corner
sections. The overlap is thereby formed only in the middle section.
According to this embodiment, the space is formed as a cavity in a
middle portion of the outer groove wall and/or in a middle portion
of the inner surface.
The upper edge of a panel may be a portion of the panel along a
short edge thereof.
The upper edge may be closer to the front side than the rear side
of the panel.
Moreover, the upper edge of the first panel may be provided in a
side wall of an indentation provided along the first short edge of
the first panel. A projection along the second short edge of the
second panel may be adapted to be inserted in the indentation.
Moreover, the upper edge of the second panel may be provided in the
second short edge of the second panel.
The first edge section may be located closer to a long edge than
the second edge section. Alternatively, the second edge section may
be located closer to a long edge than the first edge section. The
first and/or second edge sections may be arranged at corner
sections in precise analogy to the first aspect explained
above.
The locking system may be configured to be locked with a vertical
displacement of the second short edge against the first short edge.
The concept of "vertical displacement" has been defined above in
relation to the first aspect.
The locking system may be configured such that a vertical
displacement of the second short edge against the first short edge
during an initial stage of the vertical displacement bends the
strip upwards towards the second panel such that the upper locking
surface and lower locking surface overlap each other.
The strip may be configured to bend upwards towards a portion of a
front side of the second panel. The portion may be an outer portion
of the front side. The upward bending of the strip may comprise at
least one of an upward vertical displacement, a horizontal
displacement inwards, and a rotation. Optionally, the upward
bending may be combined with a twisting and/or a compression of the
strip.
The lower locking surface may be essentially horizontal.
Alternatively, the lower locking surface may be inclined. The angle
of the lower locking surface with respect to a main plane of the
second panel may be between 0.degree. and 45.degree. degrees, e.g.
15.degree., 20.degree. or 25.degree..
According to one embodiment, the lower locking surface is planar.
According to an alternative embodiment, however, the lower locking
surface may be curved. The curvature may be positive or negative,
i.e. convex or concave, in a direction perpendicular to the
vertical plane.
A shape of the lower locking surface may correspond to a shape of
the upper locking surface--partly or entirely.
A tangent line TL to the lower locking surface may intersect the
outer wall of the locking groove.
The upper locking surface may be located on the outer surface of
the locking element. The lower locking surface may be located on
the inner grove wall of the locking groove.
The upper locking surface may be spaced vertically upwards from an
upper strip surface. The upper strip surface may be surface
provided on the strip of the first short edge. The upper strip
surface may be at least partially planar. Moreover, a portion of
the upper strip surface may be curved. In a locked position, at
least a portion of the upper strip surface may engage with a
projection of the second short edge of the second panel. In
particular, at least a portion of the upper strip surface may
engage with the projection in a first edge section as well as in a
second edge section.
According to a third aspect of the disclosure a set of essentially
identical floor panels are provided with a mechanical locking
system comprising a strip extending horizontally from a lower part
of a first edge and a downwardly open locking groove formed in an
adjacent second edge. The strip comprising an upwardly protruding
locking element which is configured to cooperate with the locking
groove for locking the first edge and the second edge in a
horizontal direction parallel to a main plane of the panels and in
a vertical direction perpendicularly to the horizontal
direction.
The locking element and the locking groove comprise an upper and a
lower locking surface, which are configured to lock the panels
vertically. The floor panels are characterized in that the upper
locking surface is located on an upper part of the locking element
facing an upper edge of the first panel, and that the upper locking
surface is inclined or rounded and extends from the locking element
and towards an inner part of the panel such that a tangent line to
the upper locking surface of the locking element intersects the
edge.
The upper part of the locking element may face the upper edge of
the first panel.
Moreover, the tangent line may intersect the first edge.
The tangent line may be specified in a cross-sectional side view of
the panels. The tangent line may intersect the first edge at an
upper part of the first edge.
In one non-limiting example, the upper locking surface is planar.
In this case, the planar upper locking surface may be inclined with
respect to a front side of the first panel by an angle between
0.degree. and 45.degree., e.g. 20.degree. or 25.degree.. In another
non-limiting example, the upper locking surface is rounded or,
equivalently, curved. In this case, the curvature of the upper
locking surface may be positive or negative, or put differently:
the upper locking surface may be convex or concave in a direction
perpendicular to the vertical plane. In case of a rounded upper
locking surface, tangent lines at one or several points of the
upper locking surface may intersect the first edge, as seen from a
cross-sectional side view of the panels.
A shape of the upper locking surface may correspond to a shape of
the lower locking surface--partly or entirely.
The locking system may be configured to be locked with a vertical
displacement of the second edge against the first edge.
The locking system may be configured such that a vertical
displacement of the second edge against the first edge during
locking bends the strip downwards and turns the upper part of the
locking element outwardly away from the upper edge.
The locking surfaces may be configured such that the upper and
lower locking surfaces comprise upper and lower guiding surfaces
that overlap each other during the downward bending of the
strip.
According to a fourth aspect of the disclosure, there is provided a
method for producing a locking system at edges of building panels.
The building panels comprise a core and a locking surface formed in
the core and extending essentially horizontally such that a tangent
line to a part of the locking surface intersects an essentially
vertical adjacent wall formed in the panel edge adjacent to the
locking surface. The method comprises: forming a strip at a lower
part of a first edge of a panel and a locking element at an outer
part of the protruding strip, forming a locking groove in a second
edge of the panel, and forming the essentially horizontal locking
surface in a wall of the locking groove or on the locking element
by displacing the panel against a fixed carving tool.
According to a fifth aspect of the disclosure, a set of essentially
identical floor panels are provided with a mechanical locking
system comprising a strip extending horizontally from a lower part
of a first edge and a downwardly open locking groove formed in an
adjacent second edge. The strip comprises an upwardly protruding
locking element that is configured to cooperate with the locking
groove and locks the first and the second edge in a horizontal
direction parallel to a main plane of the first and the second
panel and in a vertical direction perpendicularly to the horizontal
direction. The locking system is configured to be locked with a
vertical displacement of the second edge against the first edge,
wherein an upper portion of the strip is configured to bend upwards
towards the second panel.
Optionally, the upward bending of the strip may be combined with at
least one of a twisting or a compression of the strip and/or the
locking element.
The fifth aspect of the disclosure is largely analogous to the
first aspect, except for the final stage of the vertical
displacement downwards, wherein reference is made to the above
embodiments and examples discussed in relation therewith.
Additionally, the locking element may assume the locked position by
means of a smooth displacement upwards such that upper and lower
locking surfaces may engage with each other in the locking
position. Alternatively, it may snap into the locked position.
According to a sixth aspect of the disclosure, a set of essentially
identical floor panels are provided with a mechanical locking
system comprising a strip extending horizontally from a lower part
of a first edge and a downwardly open locking groove formed in an
adjacent second edge. The strip comprises an upwardly protruding
locking element that is configured to cooperate with the locking
groove and locks the first and the second edge in a horizontal
direction parallel to a main plane of the first and the second
panel and in a vertical direction perpendicularly to the horizontal
direction. The locking system is configured to be locked with a
vertical displacement of the second edge against the first edge,
wherein a portion of the strip is configured to be displaced in a
direction inwards by twisting and/or compressing the strip.
The sixth aspect of the disclosure is largely analogous to the
first aspect, except that the upward and downward bending have been
replaced by twisting and/or compression of the strip, wherein
reference is made to the above embodiments and examples discussed
in relation therewith. In particular, the portion of the strip may
be a portion of the locking element, e.g. an upper portion of the
locking element.
Moreover, the upper portion of the locking element may be
configured to be displaced during locking into a space provided
between an outer groove wall of the locking groove and an inner
surface of the locking element.
Additionally, the locking system may be further configured to be
locked with a displacement of the portion of the strip in a
direction outwards. For example, the strip may be untwisted and/or
decompressed at least partly towards an initial unlocked position
of the strip.
According to a seventh aspect of the disclosure, there is provided
a set of essentially identical floor panels comprising a first
panel and an adjacent second panel and being provided with a
mechanical locking system comprising a strip extending horizontally
from a lower part of a first edge of the first panel and a first
downwardly open locking groove and a second downwardly open locking
groove formed in a second edge of the second panel. The strip
comprises a first upwardly protruding locking element and a second
upwardly protruding locking element provided inwardly of the first
locking element. Moreover, the second locking element is configured
to cooperate with the second locking groove and to lock the first
and the second edges in a horizontal direction perpendicular to a
vertical plane defined by the joint adjacent first and second
edges. The first locking element is configured to cooperate with
the first locking groove and to lock the first and second edges in
a vertical direction perpendicularly to said horizontal direction.
The locking system is configured to be locked with a vertical
displacement of the second edge against the first edge whereby an
upper portion of the locking element is displaced into a space.
The space is defined by a cavity between an outer groove wall of
the first locking groove and an inner surface of the first locking
element in a locked state of the panels.
According to one embodiment, the first and the second locking
grooves are separated by a downwardly extending projection.
According to another embodiment, the first and the second locking
groove are part of a common groove. The common groove may have an
inner wall coinciding with a wall of the first locking groove and
an outer wall coinciding with a wall of the second locking groove.
Moreover, the common groove may have an intermediate wall
connecting upper groove walls of the first and the second locking
groove.
The seventh aspect of the disclosure is largely analogous to the
first aspect, wherein reference is made to the above embodiments
and examples discussed in relation therewith. In particular, it is
understood that the upper portion of the locking element may
optionally bend upwards, may be compressed and/or twisted, and may
possibly also be bended downwards. Also, all the embodiments of the
space according to the first aspect may be combined with the
seventh aspect.
More generally, it is emphasized that the embodiments according to
the various aspects of the disclosure may be combined in part or in
their entirety with each other. Additionally, it is understood that
in all of the above aspects the bending, twisting, compression, or
deformation may be elastic or inelastic.
BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure will in the following be described in connection to
exemplary embodiments and in greater detail with reference to the
appended exemplary drawings, wherein:
FIGS. 1a-1g illustrate a fold down locking systems according to
known principles.
FIGS. 2a-2c illustrate known principles to form locking
systems.
FIGS. 3a-3e illustrate vertical folding and edge separation.
FIGS. 4a-4f illustrate bending of protruding parts.
FIGS. 5a-5b illustrate a first and a second edge section of a
locking system according to one embodiment.
FIGS. 6a-6b illustrate the first and second edge sections of the
locking system in FIGS. 5a-5b in a locked position.
FIGS. 7a-7d illustrate alternative embodiments of the first and
second edge sections.
FIGS. 8a-8c illustrate a vertical displacement of a first edge
section according to an embodiment.
FIGS. 9a-9e illustrate a vertical displacement of a second edge
section according to an embodiment.
FIGS. 10a-10c illustrate jumping tool heads and rotating carving
tools according to an embodiment.
FIGS. 11a-11f illustrate forming of an edge section with jumping
tool heads according to an embodiment.
FIGS. 12a-12b illustrate forming with carving tools according to
different embodiments.
FIGS. 13a-13e illustrate a panel edge comprising a first and a
second edge section according to an embodiment.
FIGS. 14a-14e illustrate different embodiments of locking systems
and their formation.
FIGS. 15a-15d illustrate a locking system according to a second
principle.
FIGS. 16a-16c illustrate a locking system edge section according to
the second principle.
FIGS. 17a-17d illustrate a method to strengthen a protruding part
according to an embodiment.
FIGS. 18a-18f illustrate an embodiment of a production method to
form a locking system.
FIGS. 19a-19f illustrate another embodiment of a production method
to form a locking system.
FIGS. 20a-20d illustrate locking of long and short edges according
to an embodiment and forming of a locking system according to an
embodiment.
FIGS. 21a-21e illustrate a long edge locking system according to an
embodiment.
FIGS. 22a-22d illustrate a long edge locking system according to an
embodiment.
FIGS. 23a-23d illustrate locking of furniture components according
to an embodiment.
FIGS. 24a-24f illustrate a locking system formed according to a
third principle.
FIGS. 25a-25d illustrate various embodiments of flex grooves
provided in the second floor panel.
FIGS. 26a-26b illustrate various embodiments of slits provided in
the first floor panel.
FIGS. 27a-27c illustrate an embodiment with a flexible and a
bendable locking element.
DETAILED DESCRIPTION
FIGS. 1a-1f show some examples of known fold down locking systems
made in one piece with the core 5 that are intended to lock short
edges with a vertical displacement of a second edge of a second
panel 1' against a first edge of a first panel 1. All systems
comprise a horizontally protruding strip 6 with a locking element 8
in the first edge of the first panel 1 that cooperates with a
locking groove 14 in the second edge of the second panel 1' and
locks the edges of the panels 1, 1' horizontally. Different methods
are used to lock the edges vertically.
FIG. 1a shows that a small tongue 10 that cooperates with a tongue
groove 9 may be used for the vertical locking. Compression of the
tongue 10 is required to accomplish the locking. The upper edges
are, during the vertical displacement, spaced from each other with
a space S that corresponds to the horizontal protrusion of the
tongue 10. The adjacent edges must be pulled together during the
final stage of the locking. The friction between the long edges,
that during the final stage of the locking are practically aligned
horizontally and are in a locked position, prevents such pulling
together and there is a major risk that the edges are locked with a
space or that the locking element 8 is damaged. A considerable
pressure force is required to press the edges together and
thickness tolerances may create further problems, especially if the
second panel 1' is thicker than the first panel 1 and will hit the
subfloor before the upper surfaces are aligned horizontally. The
locking system is not suitable to lock panels comprising, for
example, an HDF core or other non-compressible materials.
FIG. 1b shows a similar locking system with two tongues 10a, 10b
and two tongue grooves 9a, 9b. This system requires material
compression and creates edge separation during locking. The locking
surfaces are almost vertical and have a locking angle LA of about
60 degrees against a horizontal plane H. The protruding tongues are
very small and protrude a few tenths of a millimeter and this
corresponds to normal production tolerances resulting in locking
system that are not possible to lock or without any overlapping
locking surfaces.
FIG. 1c shows a locking system with two tongues 10a, 10b. The
locking element comprises a locking surface that is inclined
upwardly towards the upper edge in order to increase the vertical
locking strength. This locking system is even more difficult to
lock than the locking systems described above and suffers from the
same disadvantages.
FIG. 1d shows an embodiment that is based on downwardly protruding
locking elements that are intended to bend inwardly against each
other such that two tongues 10a, 10b may be inserted into tongue
grooves. The flexibility that may be obtained over the limited
vertical extension of the locking elements in an HDF material is
not sufficient to obtain a locking force necessary for flooring
applications. However, the locking system eliminates separation
forces during locking.
FIG. 1e shows a locking system wherein similar flexibility is
obtained with a groove formed behind the locking groove 14. Such
locking systems suffer from the same disadvantages as the locking
system shown in FIG. 1d. Similar locking system may also comprise
locking surfaces 10b, 9b that are shortened in regions, for example
as described in WO 2010/100046, in order to reduce damages of the
locking means during installation when material is compressed. In
practice no reduction of damages may be obtained.
FIG. 1f shows a locking system comprising a strip 6 that is bended
downwards during the vertical displacement. The locking system is
intended to be used together with an installation method wherein
the long edges of the first and the second panels are in an angled
position such that the friction forces are reduced to a level where
the locking element during upward snapping is capable to
automatically pull the edges together. The major disadvantage is
that the installation must be made with panels in angled position
and this is more complicated than the conventional single action
fold down installation.
FIG. 1g shows locking systems that may comprise slits 6a in the
locking strip, for example as described in US 2010/0037550 or slits
14a behind the locking groove, for example as described in WO
2008/116623. Such slits may increase the flexibility and the
horizontal displacement possibilities of the locking elements
considerably and a very easy locking may be obtained. The main
problem is that such slits also increase the vertical flexibility
and flexibility. This will result in a very low locking strength in
the vertical direction. Therefore attempts to introduce such
locking systems have failed.
FIGS. 2a-2c show that the geometry of the locking systems is
restricted in several ways by the production methods wherein
double-end tenors comprising a chain 33, a belt 34 and several
large rotating tools 17 with a diameter of about 20 cm are used.
FIGS. 2a and 2b show that efficient production methods require that
grooves and protrusions are formed with rotating tools 17 that
rotate vertically or horizontally or that are angled away from the
chain 33 and the belt 34. FIG. 2c shows that only essentially
vertical locking surfaces may be formed on an inner part of the
locking element 8 or on the locking groove 14 and that very small
rotating tools with a low milling capacity may be used. Several of
the known locking systems are not possible to produce in a cost
efficient way.
FIGS. 3a-3e explain the separation forces that may occur during
vertical folding when a second panel 1' is angled against a
previously installed panel 1'' in a previous row and wherein this
angling action also connects a short edge of the second panel 1' to
a short edge of a first panel 1 as shown in FIG. 3a. The short
edges are locked with a scissor like movement wherein the short
edges are gradually locked from one long edge to the other long
edge. The adjacent short edges of the first and the second panels
1, 1' have along their edges a start section 30 that becomes active
during a first initial step of the folding action, a middle section
31 that becomes active during a second stage of the folding action
and an end section 32 that becomes active during a final third step
of the folding action.
The shown locking system is based on an embodiment with a strip 6
that during vertical displacement bends downwards and thereafter
snaps upwards. FIG. 3b shows that one part of the edge, that is
close to the long edge where the angling takes place, is almost in
locked position, as shown by the cross section A-A, when the
locking element 8 and the locking groove 14 of middle sections B-B
are still spaced from each other vertically, as shown in FIG. 3c,
and when edge sections C-C that are most distant to the long edge
where angling takes place are spaced from each other vertically
without any contact between the cross sections C-C as shown in FIG.
3d. FIG. 3e shows the final step of the locking when the edges must
be pulled together with a pulling force that is sufficient to
overcome the friction between long edges of the first installed
panel 1'' and the second panel 1'. The friction may be substantial,
especially when the panels are long or when a high friction
material is used as a core. The high friction is to a large extent
caused by the geometry of the long edge locking system that must be
formed with a tight fit between the tongue and the tongue groove in
order to avoid squeaking sound.
FIGS. 4a and 4b show a one piece locking system formed in a
laminate floor panel comprising an HDF core. The locking system is
locked with horizontal snapping. The HDF material comprises wood
fibres 24 that during HDF production obtain an essentially
horizontal position in the core material. The density profile is
such that the upper 5a and the lower 5b parts of the core 5 have a
higher density than the middle parts. These outer portions are also
reinforced by the melamine resin from the impregnated paper of the
surface 2 and in the balancing layers 3 that during lamination
penetrates into the core 5. This allows that a strong and flexible
strip 6 may be formed that, during locking, bends downwards. The
snapping function is supported by the upper lip 9' that bends
slightly upwards and the protruding tongue 10 that bends slightly
downwards. The locking element may easily be formed with a high
locking angle and with essentially vertical locking surfaces.
As a comparison, bending of vertically protruding locking elements
8 are shown in FIGS. 4c-4f. FIGS. 4c and 4d show a locking element
8 that during vertical displacement is bended outwardly. The
bending takes place in the rather soft part of the HDF core and a
crack 23 will generally occur in the lower part of the locking
element 8. FIGS. 4e and 4f show a locking element 8 that is used to
lock against a locking groove 14 in a horizontal H and a vertical
direction V. The locking can only take place with material
compression and this causes damages and cracks 23, 23' in the
locking system.
FIGS. 5a and 5b show a first embodiment of the disclosure according
to a first main principle. A set of similar floor panels 1, 1' are
provided, wherein each floor panel preferably comprises a surface
layer 2, a core 5, a balancing layer 3 and a first and a second
short edge. A first short edge 4c of a first floor panel 1 may be
locked to an adjacent second short edge 4d of a similar second
floor panel 1' with a vertical displacement of the second edge
against the first edge. According to the present embodiment, the
vertical displacement is a vertical scissor movement caused by the
same angling action that is used to connect the long edges of the
panels. The first short edge 4c comprises a horizontally protruding
strip 6 with a vertically protruding locking element 8 at its outer
part that cooperates with a downwardly open locking groove 14
formed in the adjacent second edge 4d.
According to the present embodiment, the locking element 8 is
essentially rigid and is not intended to be bended or compressed
during locking that contrary to known technology is accomplished
essentially with a horizontal displacement of the upper part of the
locking element 8 towards the upper first edge 43. By essentially
rigid is here meant that during locking the locking element itself
is bended and/or compressed in a horizontal direction by a distance
HD that is less than 50% of a horizontally protruding upper locking
surface 11a located in the upper part of the locking element 8 as
shown in FIG. 6b. The displacement of the locking element 8 is
mainly accomplished with a bending and/or deformation of the strip
6. The locking element comprises an inner surface 8a, an outer
surface 8b and an upper or top surface 8c. The inner surface 8a is
closer to an upper edge 43 of the first panel 1 than the outer
surface 8b. More specifically, a horizontal distance between the
inner surface 8a and the upper edge 43 is smaller than a horizontal
distance between the outer surface 8b and the upper edge 43.
According to the present embodiment, the upper edge 43 is a portion
of the first edge close to the front side of the first panel 1.
Moreover, the upper edge 43 is provided in a side wall 45 of an
indentation 44 which is provided in the first edge. The indentation
44 is upwardly open and, in a locked position, an upper support
surface 16 of a projection 46 provided in the second edge engages
with a lower support surface 15 of the indentation which is a
portion of an upper strip surface 6a of the strip 6. The locking
groove 14 comprises an outer groove wall 14a, an inner groove wall
14b and an upper groove wall 14c.
The projection 46 is provided outside of the locking groove 14 and
share the outer groove wall 14a with the locking groove 14. The
outer groove wall 14a is closer to an upper edge 43' of the second
panel 1' than the inner groove wall 14b. More specifically, a
horizontal distance between the outer groove wall 14a and the upper
edge 43' is smaller than a horizontal distance between the inner
groove wall 14b and the upper edge 43'. The locking element 8
comprises an upper locking surface 11a formed in the outer surface
8b of the locking element 8 that cooperates with a lower locking
surface 11b formed in the inner groove wall 14b and that locks the
adjacent edges in a vertical direction. The upper 11a and the lower
11b locking surfaces are spaced vertically upwards from the upper
surface 6a of the strip 6. For example, the upper 11a and the lower
11b locking surfaces may be spaced vertically upwards with a
vertical locking distance VLD from the entire upper surface 6a or
from an uppermost part of the upper surface 6a, e.g. the lower
support surface 15 of the indentation 40. In non-limiting examples,
VLD may be between 20% and 70%, e.g. 30%, 40% or 50%, of a
thickness T of the floor panels in the vertical direction. The
locking element 8 comprises a first locking surface 12a formed in
the inner surface 8a of the locking element 8 that cooperates with
a second locking surface 12b formed in the outer groove wall 14a
and that locks the adjacent edges in a horizontal direction.
According to an alternative embodiment, the locking element 8 may
be configured to bend during locking.
Adjacent edges comprise in locked position a first edge section 7a
and a second edge section 7b. The edge sections are characterized
in that a cross section of the locking groove 14 and/or a cross
section of the locking element 8 varies along the adjacent edges of
the panels 1, 1' which are formed with a basic geometry that is
thereafter modified such that the first 7a and the second 7b
cooperating edge sections are formed with different geometries and
different locking functions. Here, the geometries and cross
sections are specified in a side view of the panels as shown in
FIGS. 5a and 5b.
The first edge section 7a is preferably a start section 30 that
becomes active during a first initial step of the folding action
and the second edge section 7b is preferably a subsequent section
31 or a middle section 31 that becomes active during a second step
of the folding action.
It is clear that, according to an alternative embodiment, the
second edge section 7b may be a start section 30 that becomes
active during a first initial step of the folding action and that
the first edge section 7a may be a subsequent section 31 or a
middle section 31 that becomes active during a second step of the
folding action. This is shown in FIG. 26b.
FIG. 5a shows a first cooperating edge section 7a that is used to
prevent edge separation during locking and to lock adjacent edges
horizontally in the locked position. The first edge section 7a has
no vertical locking function since one of the locking surfaces, in
this preferred embodiment the upper locking surface 11a, has been
removed. The first 12a and the second 12b locking surfaces are
preferably vertical and they are used to guide the second panel 1'
during the vertical displacement along a vertical plane VP that
intersects the upper and outer edge 21 of the first panel 1.
The first 12a and the second 12b locking surfaces may be inclined
against the vertical plane VP. Such geometry may be used to
facilitate unlocking of the short edges with an angling action. A
locking system with vertical first 12a and second 12b locking
surfaces may be unlocked with a sliding action along the short
edges.
FIG. 5b shows the second edge section 7b that is used to lock the
adjacent edges vertically. The second edge section 7b cannot
prevent edge separation and has no horizontal locking function
since a part of the locking element 8 and/or the locking groove 14
has been removed in order to form a space S along a horizontal
plane HP that allows a turning or displacement of the locking
element 8 inwardly during locking when the second edge 1' is
displaced vertically along the vertical plane VP.
The turning of the locking element 8 is mainly caused by an upward
bending of a part of the strip 6 within the second edge section 7b
that takes place when a horizontal pressure is applied by a part of
the inner groove wall 14b on the outer surface 8b of the locking
element 8 during the vertical displacement of the second edge 4d
against the first edge 4c. Such locking function provides major
advantages. No material compression is required and the material
properties of the protruding strip may be used to obtain the
necessary flexibility that is needed to displace the upper part of
the locking element 8 in order to bring the upper and lower locking
surfaces 11a, 11b in a locked position.
According to the present embodiment, the space S has a vertical
extension substantially corresponding to a vertical extension of
the inner surface 8a so that it extends down to the upper strip
surface 6a. It is clear that, according to alternative embodiments
(not shown), the space S may have a smaller vertical extension.
Preferably, however, the space S is located at an upper part of the
locking element 8. Moreover, the vertical extension is preferably
larger than a vertical extension of an upper protruding part 25
formed on an outer and upper part of the locking element 8, e.g.
15, 2 or 3 times larger.
In a first example, the vertical extension of the space S varies
along the edge. The vertical extension may vary along the edge from
a minimal vertical extension to a maximal vertical extension and
then, optionally, back to a minimal vertical extension. The
variation may be smooth.
In a second example, the vertical extension of the space S is
constant along the edge. A first and a second wall of the space S
that are spaced from each other along the edge may be vertical and
parallel.
By way of example, the space S may be formed by means of milling,
scraping, punching, perforation or cutting.
The strip 6 and the locking element 8 are during locking twisted
along the first short edge. In the first edge section 7a, the strip
6 is essentially in a flat horizontal position during locking and
in the second edge section 7b the strip 6 is bended upwards and the
locking element 8 with its upper locking surface is turned and/or
displaced inwardly during locking.
Optionally, or alternatively, at least portions of the strip 6 may
be twisted and/or compressed during locking. For example, a portion
between a lower part of the strip 6b and the upper strip surface 6a
and/or the locking element 8 of the strip 6 may be twisted and/or
compressed. The twisting may occur at least around an axis that is
perpendicular to the vertical plane VP. The compression may occur
at least inwardly in a horizontal direction that is perpendicular
to the vertical plane VP. In particular, the strip 6 may be twisted
in the transition regions between the first 7a and second 7b edge
sections. Moreover, the strip 6 may become compressed in the second
edge section 7b and such compression may facilitate a displacement
of the locking element 8 even in rather rigid materials since the
material content of the strip 6 is much larger than the material
content of the locking element 8. As an example it may be mentioned
that the locking element 8 may have a horizontal extension of about
4 mm and the strip 6 may protrude horizontally about 8 mm from the
side wall 45 and to the inner surface 8a of the locking element. At
a compression of 1%, the locking element will contribute with 0.04
mm or with about 1/3 of a total compression and the strip with 0.08
mm or with about 2/3 of the total compression.
Generally, the locking element in an HDF based laminate floor must
be displaced horizontally with a distance of at least 0.2 mm in
order to provide sufficient locking strength. 0.4 mm is even more
preferred. Depending on the joint geometry and material properties
about 1/3 of the necessary displacement may be accomplished with
material compression and 2/3 with bending and turning or twisting
of the strip and the locking element.
The upper 11a and lower 11b locking surfaces are preferably
essentially horizontal. The locking surfaces are in the showed
embodiment inclined against a horizontal plane HP with a locking
angle LA that is about 20 degrees. The locking angle LA is
preferably 0-45 degrees. Locking surfaces with low locking angles
are preferred since they provide a stronger vertical locking. The
most preferred locking angle LA is about 5-25 degrees. However it
is possible to reach sufficient locking strength in some
applications with locking angles between 45 and 60 degrees. Even
higher locking angles may be used but such geometries will decrease
the locking strengths considerably.
FIGS. 6a and 6b show the first 7a and the second 7b edge sections
in a locked position. The first edge section 7a is configured such
that the outer groove wall 14a of the locking groove 14 and the
inner surface 8a of the locking element 8 are in contact with each
other along a horizontal plane HP and lock the first short edge and
the second short edge horizontally and the second edge section 7b
is configured such that along the same horizontal plane HP there is
a space S between the outer groove wall 14a of the locking groove
14 and the inner surface 8a of the locking element 8. The space S
allows that the locking element 8 may be turned and/or displaced
inwardly. The first edge section 7a is also preferably configured
such that there is no vertical locking and no turning and/or
displacement of the locking element 8 since at least one of the
locking surfaces 11a, 11b has been removed and the second edge
section 7b is configured such that it comprises upper 11a and lower
11b locking surfaces that lock the edges vertically and upper and
lower 26 protruding parts that during locking press, displace
and/or turn the locking element 8 inwardly. Also compression and/or
twisting are possible.
FIG. 6a shows the first edge section 7a in a locked position. The
first locking surface 12a formed on the inner surface 8a of the
locking element 8 is in contact with the second locking surface 12b
formed on the inner groove wall 14a of the locking groove 14. The
first 12a and the second 12b locking surfaces lock the adjacent
edges horizontally and prevent a horizontal separation of the
panels 1, 1'.
FIG. 6b shows the second edge section 7b in a locked position. The
upper locking surface 11a formed on the outer surface 8b of the
locking element 8 is in contact with the lower locking surface 11b
formed on the inner groove wall 14b of the locking groove 14. The
upper 11a and lower 11b locking surfaces lock the adjacent edges
vertically and prevent a vertical separation of the panels 1,
1'.
According to the present embodiment, there is an intermediate
cavity 47 provided between a portion of the upper support surface
16 and a portion of the upper strip surface 6a. Since a thickness
of the strip 6 in this area is smaller than at the location of the
lower support surface 15, the strip may be bended more easily. The
upper support surface 16 preferably is a planar surface and the
projection 50 preferably has a constant thickness in a direction
perpendicular to the vertical plane VP as measured from its surface
layer 2. The thickness is preferably also constant along the edge
of the second panel 1'.
According to an alternative embodiment (not shown), however, the
thickness of the projection 50 may vary in a direction
perpendicular to the vertical plane VP.
Thereby, least a portion of the projection 46 may extend below the
lower support surface 15.
The space S is an essential feature in this embodiment of the
disclosure. A horizontal extension of the space S along a
horizontal plane HP that intersects the upper 11a and lower 11b
locking surfaces preferably exceeds a horizontal distance HD of the
upper and lower locking surfaces. Here, the horizontal extension of
the space S may be a maximal horizontal extension.
FIG. 7a shows a preferred embodiment of the first edge section 7a
where a part of the inner groove wall 14b and the lower locking
surface 11b have been removed. FIG. 7b shows a preferred embodiment
of the second edge section 7b where a part of the outer groove wall
14a has been removed in order to form the space S that allows the
locking element 8 to turn inwardly during locking.
According to the present embodiment, the space S has a vertical
extension substantially corresponding to a vertical extension of
the outer groove wall 14a so that it extends up to the upper groove
wall 14c. It is clear that, according to alternative embodiments
(not shown), the space S may have a smaller vertical extension.
Preferably, however, the space S is located adjacent to the upper
groove wall 14c. Moreover, the vertical extension is preferably
larger than a vertical extension of the upper protruding part 25,
e.g. 1.5, 2 or 3 times larger.
The vertical extension of the space S may vary or may be constant
along the edge as explained above in relation to the embodiment in
FIGS. 5a-b.
FIGS. 7c and 7d show that the embodiments shown in FIGS. 5a, 5b and
7a, 7b may be combined. As shown in FIG. 7c, the first edge section
7a configured to prevent edge separation and to lock horizontally
may be formed according to FIG. 7a and the second edge section 7b
comprising the space S and configured to bend and to lock
vertically may be formed according to FIGS. 5b and 6b.
Alternatively, as shown in FIG. 7d, the first edge 7a section may
be formed according to FIG. 5a or 6a and the second edge section 7b
may be formed according to FIG. 7b.
It is stressed that any of the additional and/or optional features
described above in relation to the embodiments in FIGS. 5a-5b,
6a-6b and 7a-7b also may be combined with the embodiment according
to FIGS. 7c and 7d.
In any of the embodiments in the present disclosure, there may also
be an upper cavity 48 between the upper groove wall 14c and the
upper surface 8c in a locked position of the first 1 and second 1'
panel. The upper cavity 48 may be located in the second edge second
7b and optionally also in the first edge section 7a.
Thereby, there is more space provided in the second edge section 7b
for the upwardly bending locking element 8.
Additionally, it is clear that there may be at least one first edge
section 7a and at least one second edge section 7b. In particular,
there may be a plurality of first 7a and second 7b edge sections
along the edge. The first 7a and second 7b edge sections may be
arranged alternately. In particular, the edge sections may be
arranged in a sequence along the edges such as {7a, 7b, 7a}, {7a,
7b, 7a, 7b, 7a} or {7a, 7b, 7a, 7b, 7a, 7b, 7a} with a first edge
section 7a at the corners of the edges.
Alternatively, there may be a second edge section 7b at the corners
of the edges so that a sequence such as {7b, 7a, 7b}, {7b, 7a, 7b,
7a, 7b} or {7b, 7a, 7b, 7a, 7b, 7a, 7b} is provided along the
edges.
FIGS. 8a-8c show vertical displacement of the first edge section 7a
that according to the present embodiment constitutes a start
section 30 and that is active from an initial first step of the
folding action. The embodiments in FIGS. 8a-8c and 9a-9d may be
understood in conjunction with FIG. 13a. The end section 32 that is
active during the final step of the folding action is preferably
also formed with geometry similar or identical to the first edge
section 7a. The start 30 and end 32 sections are arranged at a
first and a second corner section, respectively, of the first 1 and
second 1' panels, adjacent to their long edges 4a, 4b. A part of
the inner surface 8a of the locking element 8 is formed as a first
locking surface 12a that is essentially parallel with a vertical
plane VP and a part of the outer groove wall 14a is formed as a
cooperating second locking surface 12b that preferably is
essentially parallel with the vertical plane VP. The first and the
second locking surfaces 12a, 12b guide the edges of the panels 1,
1' during the folding action and counteract separation forces that
are caused by the second edge section 7b that becomes active in a
second step of the folding action when the major part of the first
section 7a is in a horizontally locked position with the first 12a
and the second 12b locking surfaces in contact with each other as
shown in FIG. 8b. FIG. 8c shows the adjacent edges in a final
locked position.
FIGS. 9a-9d show locking of the second edge section 7b that
according to the present embodiment constitutes a middle section 31
and that is active from a second step of the folding action when
the guiding and locking surfaces 12a, 12b of the first edge section
7a are active and in contact with each other. FIG. 9a shows that a
horizontally extending upper protruding part 25 is formed on the
outer and upper part of the locking element 8 and above the upper
locking surface 11a and is in initial contact with a sliding
surface 27 formed on a lower part of the inner groove wall 14b. The
sliding surface 27 extends essentially vertically upwards to a
horizontally extending lower protruding part 26 formed below the
lower locking surface 11b. The sliding surface 27 will during the
vertical displacement create a pressure force F against the upper
protruding part 25 and this will press the locking element 8
inwardly towards the upper edge of the first panel 1 and bend the
strip 6 upwards as shown in FIG. 9b.
The pressure against the locking element 8 will create separation
forces tending to displace the second panel 1' horizontally away
from the first panel 1, but that are counteracted by the first and
the second locking surfaces 12a, 12b of the first edge section 7a.
The pressure that is needed to lock the edges may be reduced if the
sliding surface 27 is essentially vertical and extends over a
substantial vertical sliding distance SD, measured vertically over
a distance where the inner groove wall 14b is in contact with the
outer surface 8b of the locking element during the vertical
displacement, and/or if the vertical extension VE of the locking
element 8, defined as the vertical distance from the lowest point
on the upper surface of the strip 6a and to the upper surface 8c of
the locking element 8, is large. Preferably, the inclination of the
sliding surface 27 is 10-30 degrees in relation to a vertical plane
VP and the vertical sliding distance SD is 0.2-0.6 times the size
of floor thickness T. A vertical sliding distance SD of 0.3-0.5
times the size of floor thickness T is even more preferred.
Preferably, the vertical extension VE of the locking element 8 is
0.1-0.6 times the size of floor thickness T.0.2*T-0.5*T is even
more preferred.
An upward bending of a strip is suitable for wood based cores, such
as for example HDF, since the fibres in the upper part of the strip
that are sensitive to pulling forces and shear stress will be
compressed and the fibres in the lower and stronger part of the
strip that are more resistant to pulling forces and shear stress
will be stretched.
A considerable amount of bending deflection 29 may be reached and a
strip 6 that extends horizontally from the upper edge about 8 mm or
with the same distance as the floor thickness T may be bended
upwards about 0.05-1.0 mm, e.g. 0.1 mm or 0.5 mm. Here, a bending
deflection 29 is defined as a vertical distance, in a direction
perpendicular to the horizontal plane HP, from a horizontal plane
HR being parallel and essentially coinciding with the rear side 60
of the first panel 1 in an unlocked state to an outermost and
lowermost part of the strip 6. Thus, the bending deflection 29
typically varies along the edge of the first panel 1 and also
varies during the various stages of the locking. A maximal bending
deflection 29 may be located in a middle portion of a second edge
section 7b along a length direction of the edges.
FIG. 9c shows an embodiment according to which the upper and lower
locking surfaces 11a, 11b will start to overlap each other already
when the upper surfaces of panels 1, 1' are still spaced
vertically. This means that the strip 6 will pull the second panel
1' comprising an upper support surface 16 towards a lower support
surface 15 formed on the edge of a first panel 1 to a final locked
position and this will reduce the pressure force that is required
to lock the panels 1, 1'. An additional advantage is that the
vertical locking may be made with a pretension such that the strip
6 is slightly bended upwards in locked position as shown in FIG.
9d. The remaining bending deflection 29 in the locked position may
be about 0.05-0.30 mm, e.g. 0.1-0.2 mm, when the lower and upper
support surfaces 15, 16 are in contact with each other. According
to this embodiment, the locking system is configured such that in
the locked position a middle section 31 comprises a strip 6 that is
upwardly bended compared to its unlocked position and a start
section 30 that comprises a strip which is essentially in a similar
locked position than in an unlocked position. It is understood that
there may be transition parts between the first 7a and second 7b
edge sections wherein the strip is upwardly bended.
According to a different embodiment, the strip of the start section
may even be slightly bended backwards in locked position.
Another advantage is that problems related to thickness tolerances
of the panels may be avoided since even in the case that the second
panel 1' is thicker than the first panel 1 and normally will hit
the sub floor 35 before the upper surfaces are in the same
horizontal plane, locking may be made with offset upper edges where
the surface of the second edge is above the first edge and the
strip will pull the panels to a correct position with horizontally
aligned upper surfaces and upper and lower support surfaces 15, 16
in contact with each other. Such locking function is also favorable
when the floor panels are installed on a soft underlay, such as
foam, and a counter-pressure from the sub floor cannot be used to
prevent a downward bending of the strip 6.
A strip formed in soft materials such as an LVT core comprising
thermoplastic materials and filler may not snap back towards the
initial position after the locking.
This may be solved with a joint geometry where the upper groove
wall 14c is formed to be in contact with the upper surface 8c of
the locking element 8 during the final stage of the locking action
such that the locking element 8 and the strip 6 are pressed
downwards. The locking system may also be formed with an outer and
lower support surface 15a that cooperates with the projection 46
during locking in order to press the strip 6 downward to or towards
its initial position as shown in FIG. 9b.
FIG. 9e shows that the strip 6 may be formed such that an inner
part 6c is bended slightly downwards and an outer part 6d is bended
slightly upwards. Such strip bending and compression will also bend
and displace the locking element 8 inwards toward the first upper
edge 43. The upper and lower locking surfaces 11a, 11b may even in
this embodiment overlap each other during locking when the first
and the second panels are still vertically displaced in relation to
the final locked position with the second panel 1' spaced
vertically upward from the first panel 1.
FIGS. 10a and 10b show that rotating jumping tool heads 18 may be
displaced horizontally and may be used to form cavities 42,
nonlinear grooves 36 or may be displaced vertically and may be used
to form grooves 37 with different depths in a panel 1. FIG. 10c
shows another cost efficient method to form cavities 42 or grooves
36, 37 with a rotating carving tool 40. A tool rotation of the
rotating carving tool 40 is synchronized with a displacement of the
panel 1 and each tooth 41 forms one cavity 42 at a predetermined
position and with a predetermined horizontal extension along an
edge of a panel 1. It is not necessary to displace the carving tool
40 vertically. A carving tool 40 may have several sets of teeth 41
and each set may be used to form one cavity. The cavities 42 may
have different cross sections depending on the geometry of the
teeth. The panel 1 may be displaced with or against the tool
rotation.
This production technology may be used to form the first 7a and the
second 7b edge sections.
FIGS. 11a-11f show that a rotating tool 17 may be displaced
horizontally along the locking element 8 or the locking groove 14
and a first 7a and a second 7b edge section will be formed when the
tool initially removes the upper protruding part 25 of the locking
element and then a part of the inner surface 8a of the locking
element, or initially removes the lower protruding part 26 of the
locking groove 14 and then a part of the outer groove wall 14a of
the locking groove 14. This method may be used to form the edge
sections in a very efficient way. The horizontal displacement of
the rotation tool 17 may be at or less than about 1.0 mm, e.g. 0.5
mm or 0.2 mm.
FIGS. 12a-12b show a fixed carving tool 22 and a part of the edge
of the second panel 1' that is shown with the surface layer 2
pointing downwards. Carving may be used to form an essentially
horizontal locking surface 11b in an inner groove wall 14b of the
locking groove 14 even when the locking surface 11b comprises a
tangent line TL that intersects the outer groove wall 14a. A more
detailed description of carving may be found in WO 2013/191632.
FIG. 13a shows a vertical folding of a second panel 1' against a
first panel 1, comprising a locking system according to FIGS. 8a-c
and 9a-d. The edges comprise a start section 30 that is formed as a
first section 7a, a middle section 31 that is formed as a second
section 7b and an end section 32 that is formed as a first section
7a. The first 12a and second 12b locking surfaces are guiding
surfaces of the start section that prevent separation and the
panels 1, 1' are folded together with upper edges in contact. FIG.
13b shows an embodiment of a short edge 4c of the first panel 1
comprising a middle section being a second edge section 7b and
having an upper protruding part 25 with an upper locking surface
11a and a first edge section 7a on each side of the middle section
7b comprising guiding surfaces 12a. A part of the inner surface 8a
of the locking element 8 has been removed at the middle section 7b
in order to form a space S that allows an inward turning of the
locking element 8, cf. FIG. 5b. FIG. 13c is a top view of the short
edge 4c of the first panel 1 as shown in FIGS. 13a and 13b and
shows that a part of the strip 6 at a transition part 6c, located
between the first 7a and the second 7b edge section, is twisted
during the vertical folding since the strip is flat in the first
edge section 7a and bended upwards in the second section 7b. The
twisting increases the locking pressure that has to be used to lock
the edges. Twisting may be reduced or even eliminated if needed
with a horizontal cavity 28 formed in the strip 6 between the first
7a and the second 7b edge sections as shown in FIG. 13d.
FIGS. 14a-14e show different embodiments of the disclosure. The
embodiments in FIGS. 14a-e may be combined with any of the
embodiments of the disclosure. FIG. 14a shows floor panels
comprising an HDF core 5 and a strip 6 which is essentially formed
in the lower part 5b of the core 5 that has a higher density than
the middle part. At least parts of the locking groove 14 and/or the
locking element 8 may be coated with a friction reducer 22 in order
to reduce friction during locking. For example, the friction
reducer 22 may comprise wax. Other exemplary friction reducing
substances include oils. Parts of the locking groove 14 and/or the
locking element 8 may be impregnated with a reinforcement agent,
e.g. resins, in order to reinforce parts adjacent to upper and
lower locking surfaces 11a, 11b. Exemplary reinforcement agents
include a thermoplastic, a thermosetting resin or a UV curing
glue.
FIG. 14b shows a locking system formed in a rather soft core 5. The
strip 6 and the locking element 8 have been made larger. A lower
essentially horizontal locking surface 11b may be formed by an
inclined rotating tool 17 and with a locking angle LA that may be
as low as 20 degrees. It is clear that other locking angles LA are
equally conceivable. In non-limiting examples, a locking angle LA
between 0.degree. and 45.degree. may be formed by the inclined tool
17.
FIG. 14c shows that forming of the lower locking surface 11b may be
made with a rotating jumping tool that only removes material mainly
within the second edge section 7b. An advantage is that the lower
locking surface 11b may be formed with a rotating tool that will
not reduce the vertical extension of the second locking surface
12b.
FIG. 14d shows that in some embodiments the first section 7a may
comprise locking means 11a, 11b that lock the edges vertically,
preferably mainly by material compression. The locking means may be
locking surfaces 11a, 11b. In general, the edge sections 7a, 7b may
comprise complementary locking means as described in FIGS. 1a-1e,
for example a small tongue 10 and groove 9 at the adjacent edges as
shown in FIG. 1a.
FIG. 14e shows that panels 1, 1' with different thicknesses may be
produced with the same tool position in relation to the surface
layer 2. This means that the strip 6 will be thicker and more rigid
in thicker panels. This may be compensated by removal of materials
at the lower part 6d of the strip 6 and all panels may comprise a
strip 6 with similar flexibility and deflection properties.
FIGS. 15a-15d show a second principle of the disclosure. The
locking element 8 comprises an upper locking surface 11a formed at
the inner surface 8a and the locking groove 14 comprises a lower
locking surface 11b formed in the outer groove wall 14a. A strong
vertical locking may be accomplished if the locking surfaces 11a,
11b are essentially horizontal, e.g., within 20 degrees of
horizontal. Preferably, a tangent line TL of the upper locking
surface 11a intersects an adjacent wall of the upper edge.
Moreover, a tangent line TL of the lower locking surface 11b
preferably intersects an adjacent wall of the locking groove 14.
Locking is accomplished with a downward bending of the strip 6
wherein the locking element 8 is turned outwards as shown in FIG.
15b. A problem is that the strip 6 may still be in a backward
bended position and the locking surfaces 11a, 11b may be spaced
vertically when the upper edges of the panels 1, 1' are aligned
horizontally as shown in FIG. 15c.
An upper guiding surface 13a is therefore formed as an extension of
the upper locking surface 11a and a lower guiding surface 13b is
formed as an extension of the lower locking surface 11b. The
locking surfaces 11a, 11b and the guiding surfaces 13a, 13b are
configured such that the guiding surfaces 13a, 13b overlap each
other during locking and during the downward bending of the strip 6
when the upper surface 2 of the second panel 1' is spaced
vertically upwards from the upper surface 2 of the first panel
1.
FIGS. 16a-16b show that a locking system according to the second
principle may comprise a first 7a and a second edge section 7b such
that the geometry of the locking element 8 and/or the locking
groove 14 varies along the edge. Preferably, the first edge section
7a comprises only locking means that lock the edges in a horizontal
direction and the second edge section 7b, that according to this
embodiment is a middle section 31, comprises horizontal and
vertical locking means. According to the present embodiment, a
start section 30 and an end section 32 both are first edge sections
7a. An advantage of the present embodiment is that the locking may
be made with a lower pressure force that only has to be applied
when the second panel 1' is folded to a rather low locking angle
that may be about 5 degrees or lower. The removal of the upper 11a
and/or lower 11b locking surfaces within the first edge sections 7a
may only have a marginal negative influence on the vertical locking
strength since the part of the edges that constitutes a first edge
section 7a is locked vertically by the adjacent long edges 4a, 4b
as shown in FIG. 16b. FIG. 16c shows that the locking system may be
configured such that a controlled crack 23 occurs in the material
of the core 5, e.g. a material comprising wood fibres. In
non-limiting examples, the material may be HDF material or material
from a particle board. Moreover, the crack 23 may be provided
parallel to a fibre direction of the material. The crack 23 may
extend to a depth of about 1 mm to about 5 mm. The crack 23 may
extend along the entire edge of the first panel 1 or,
alternatively, only along a part thereof, e.g. in a middle part.
The advantage is that the strip 6 will be easier to bend downward
during locking than upwards in the locked position. According to
the embodiment in FIG. 16c, lower and upper support surfaces 15, 16
are formed in an upper part of the panels 1, 1'.
FIGS. 17a-17d show that a core material 5 may be locally modified
such that it becomes more suitable to form a flexible and strong
strip 6. Such a modification may be used in all embodiments of the
disclosure. FIG. 17a shows that a resin 20, for example a
thermosetting resin 20 such as, for example, melamine formaldehyde,
urea formaldehyde or phenol formaldehyde resin, may be applied in
liquid or dry powder form on a balancing paper 3 or directly on a
core material 5.
For example, the balancing paper 3 may be a melamine formaldehyde
impregnated balancing paper 3. The resin may also be locally
injected into the core 5 with high pressure. FIG. 17b shows that a
core material 5, preferably a wood based panel for example an HDF
board or a particle board, may be applied on impregnated paper 3
with the added resin 20 prior to lamination. FIG. 17c shows a floor
board after lamination when the surface layers 2 and the balancing
layer 3 have been laminated to the core 6. The resins 20 have
penetrated into the core 5 and cured during lamination under heat
and pressure. FIG. 17d shows an edge of a first panel 1 comprising
a strip 6 formed in one piece with the core 5. The strip 6 is more
flexible and comprises a higher resin content than other parts of
the core 5. The increased resin content provides a material that is
very suitable to form a strong flexible strip 6 that during locking
may be bended.
FIGS. 18a-18f show that the entire edge of the second panel 1'
comprising an essentially horizontal lower locking surface 11b
having a tangent line TL that intersects a wall of the locking
groove 14 may be formed with rotating tools 17 that are angled away
from the chain 33 and the belt 34 and a carving tool 19 that
preferably as a last machining step forms the locking surface
11b.
FIGS. 19a-19e show that the edge of the first panel 1 may be formed
initially with large rotating tools 17 that are angled away from
the chain 33 and the belt 34.
The first and the second edge sections 7a, 7b are formed with a
jumping tool 18 as shown in FIG. 19f. A rotating scraping tool may
also be used.
FIGS. 20a-20d show a locking system that is particularly suitable
and adapted to be used on the long edges of panels 1, 1' that are
locked with a fold down system according to an embodiment of the
disclosure. The locking system comprises an upper 10a and a lower
tongue 10b that cooperate with an upper 9a and a lower 9b tongue
groove and that lock the edges vertically at least in a first
direction upwards.
A locking strip 6 with a locking element 8 cooperates with a
locking groove 14 in an adjacent panel and locks the panel edges
horizontally. A lower protrusion 38 is formed on an edge of the
second panel 1' and an upper part 6a of the strip 6 locks the edges
in a second vertical direction downwards. The locking system is
configured such that a high friction is obtained between the long
edges and along the edges when they are in an almost locked
position and when the first and second locking surfaces 12a, 12b of
the first edge section 7a of the short edge locking system are in
contact with each other and the upper 11a and lower 11b locking
surfaces of the second edge section 7b are spaced vertically such
that no separation forces are active. This is explained more in
detail in FIGS. 21a-21e.
The high friction is mainly obtained with locking surfaces formed
on the locking element 8 and the locking groove 14 that are more
inclined against a horizontal plane HP and comprises a higher
locking angle LA than the so called "free angle" defined by a
tangent line TL to a circle with a radius R equal to the distance
from the locking surfaces of the locking element and the locking
groove to the upper part of the adjacent edges. FIG. 20b shows that
the locking system is configured such that in an up angled and
locked position there are at least three contact points where the
edges are pressed against each other: a first contact point Cp1
between the upper edges, a second contact point Cp2 between the
locking element 8 and the locking groove 14, and a third contact
point Cp3 between the lower tongue 10b and the lower tongue groove
9b. Alternatively, the contact points may be contact surfaces. It
is understood that each of the contact points forms a contact line
or a contact surface along the edges. FIGS. 20c and 20d show that
the locking system may be formed with a low material waste in
connection with the first cutting step comprising large rotating
saw blades 17 and carving tools 19 when a large laminated board is
separated into individual panels 1, 1'.
FIGS. 21a-21e show the position of the long 4a, 4b and short edges
4c, 4d during the vertical folding. FIG. 21a shows a second panel
1' that is angled with its long edge 4b against a long edge 4a of
previously installed panel 1'' in a previous row and folded with
its short edge 4d against a short edge 4c of an installed first
panel 1 in the same row. FIG. 21b shows the long edges 4a, 4b of
the second 1' and the previously installed panel 1'' in a partly
locked and up angled position when three contact points Cp1, Cp2,
Cp3 are pressed against each other in order to create a friction
along the long edges in an up angled position. FIG. 21c shows the
long edges 4a, 4b of the previously installed panel 1'' and the
first panel 1 in a completely locked position. FIG. 21d shows that
the first and second locking surfaces 12a, 12b are in contact with
each other in the first edge section 7a and FIG. 21e shows that at
the same time the locking element 8 and its upper protruding part
25 in the second edge section 7b is spaced from the locking groove
14 and its sliding surface 27 such that no separation forces are
active. This means that the separation forces created by the second
edge section 7b and the bending of the strip 6 are counteracted by
the first and second locking surfaces 12a, 12b of the first edge
section 7a and the friction along the long edges 4a, 4b created by
a pretension and a contact preferably at three contact points Cp1,
Cp2, Cp3 along the long edge locking system. As an example, it may
be mentioned the locking system may be formed with a first edge
section 7a that extends with an edge distance ED of about 2-8 cm,
for example 5 cm, from a long edge 4a as shown in FIG. 21a and with
a locking element comprising a vertical extension of about 0.5-6
mm, for example 2, 3 or 4 mm. The second edge section 7b may start
at a horizontal distance from a long edge of about 15-35%, e.g.
20%, of the length of the edge.
The long edges may be folded to an angle of about 1-7 degrees, for
example 3 degrees, before the locking element 8 is in contact with
the locking groove 14 and such a low angle may be used to form a
long edge locking system that creates a very high friction along
the long edges in a partly locked position where the upper part of
the locking element 8 of one long edge overlaps vertically a lower
part of the locking groove 14 of an adjacent long edge. Preferably,
the long edge locking system is configured such that a locking
angle of 3-5 degrees may be reached before the locking element and
the locking groove of the second section 7b are in contact with
each other.
FIGS. 22a-22d show embodiments of locking systems that may be
formed with pretension in a partly locked position as described
above. The locking systems according to FIGS. 22a-22d are
particularly suitable and adapted to be used on the long edges of
panels 1, 1'. The shown locking systems in FIGS. 22a-22d illustrate
that the locking systems in FIGS. 21b and 21c may be formed with a
fourth contact point Cp4 located at an upper part of a tongue 10
and a tongue groove 9.
FIG. 23a-23d show that all embodiments of the disclosure may be
used to lock for example furniture components where a second panel
1' comprising a locking groove 14 is locked vertically and
perpendicularly to a first panel 1 comprising a strip 6 and with a
locking element 8. The strip 6 may initially bend upwards or
downwards during the vertical displacement of the second panel 1'
against the first panel 1 and the locking element 8 may comprise
locking means that lock horizontally parallel to a main plane M1 of
the first panel and vertically parallel to the a plane M2 of the
second panel 1'. The main plane M1 of the first panel 1 may be
defined as a horizontal plane that is essentially parallel with a
lower side 80 of the first panel 1. The main plane M2 of the second
panel 1' may be defined as a vertical plane that is essentially
parallel with an outer side 82 of the second panel 1'. The panels
1, 1' may have a first 7a and a second 7b edge section as described
above. The first edge section 7a may be formed such that the
locking element 8 is in contact with the locking groove 14 when the
locking element 8 and the locking groove 14 of the second section
7b are spaced from each other as shown in FIGS. 23a and 23c.
FIGS. 24a-24e show that the locking system of a first 1 and a
second 1' panel may be formed with a first and a second locking
element 8, 8' and a first and a second locking groove 14, 14'.
According to the present embodiment, the first 8 and second 8'
locking elements and the first 14 and second 14' locking grooves
extend along the entire edge of the first panel 1 and second panel
1', respectively.
Alternatively, however, the second locking element 8' and the
second locking groove 14' may extend along a part of the edge of
the first panel 1 and second panel 1', respectively, wherein an
extension of the second locking element 8' is smaller than or
substantially equal to an extension of the second locking groove
14'.
The second locking element 8' and the second locking groove 14' may
be used to prevent edge separation and to lock the panels
horizontally and may replace the first and second locking surfaces
12a, 12b. Preferably, the lower and inner part(s) of the second
locking groove 14' and the upper and outer part(s) of the second
locking element 8' comprise guiding surfaces, for example rounded
parts as shown in FIG. 24a, that engage with each other and press
the upper edges towards each other such that separation forces are
counteracted. As an alternative, the one or both overlapping
locking surfaces 11a, 11b may be removed or the entire first
locking element 8 may be removed at a corner section of first edge,
e.g. between 5% and 20% of a total length of the first edge.
A vertical extension of the second locking element 8' and/or the
second locking groove 14' may vary along the first and/or second
edge, respectively. The vertical extension may vary from a maximal
extension to a minimal extension. The variation may be periodic. At
the maximal extension, a top surface of the second locking element
8' may engage with an upper groove wall of the second locking
groove 14'.
At the minimal extension, there may be a cavity between the top
surface of the second locking element 8' and the upper groove wall
of the second locking groove 14'.
A vertical flex groove 39 may be formed adjacent to and preferably
inwardly of the locking groove 14 in all embodiments of the
disclosure.
This embodiment offers the advantages that continuous grooves and
locking elements without any edge sections may be used and this
will simplify the forming of the locking system. A locking system
with high vertical and horizontal locking strength may be formed.
The space S between the first locking element 8 and the first
locking groove 14 allows a turning and/or displacement of the
locking element 8 as described in the previous embodiments. The
horizontal distance D1 between the inner surfaces 8a of the first
locking element 8 and the outer surface 8b' of the second 8'
locking element is preferably at least about 30% the floor
thickness FT in order to provide sufficient flexibility and locking
strength. The horizontal distance D1 may be as small as about 20%
of the floor thickness. More generally, D1 may be between 20% and
80% of FT. An upper part of the first locking element 8 is
preferably located closer to the panel surface than an upper part
of the second locking element 8'. Alternatively, however, the upper
part of the first locking element 8 may be located closer to the
panel surface than the upper part of the second locking element 8'.
This may reduce separation forces since the second locking element
8' will become active before the first element 8 is in contact with
the locking groove 14.
FIG. 24f shows a more compact version wherein the first 14 and the
second 14' locking grooves are connected to each other. The second
locking groove 14' forms an outer part of the first locking groove
14. The locking system may have one or a plurality of pairs lower
and upper support surfaces that are configured to cooperate in a
locked state of the panels. For example, support surfaces 15, 16
may be provided between the inner and lower part of the first panel
1 and the outer and lower part of the second panel 1', and/or
support surfaces 15', 16' may be provided between the upper part of
the second locking element 8' and the upper part of the second
locking groove 14'. A part of the locking strip 6 and the second
locking element 8' protruding beyond an outer strip portion 50,
preferably outside the second locking element 8', may be removed at
a corner section of the first edge in order to eliminate separation
forces during the initial stage of the locking when the second
panel 1' is angled down towards the first panel 1.
FIGS. 25a-25e illustrate various embodiments of one or a plurality
of flex grooves 39 For simplicity, the second locking element 8'
and the second locking groove 14' are not shown but may be formed
in the edge of the first 1 and second panel 1' in all embodiments
of FIGS. 25a-25d and 26a-26d. FIG. 25a shows a first panel 1 with a
plurality of first and second edge sections 7a, 7b and a flex
groove 39 that extends along the entire edge of the second panel
1'. FIG. 25a also shows that at least a part of the projection 46
may be removed and this may in some embodiments simplify the
forming of second edge section 7b.
The flex groove 39 may also extend along a part of the edge of the
second panel 1'.
In the embodiment in FIG. 25b the flex groove 39 has two walls in a
direction along the edge and is located in a center portion of the
edge in the length direction thereof. Preferably the flex groove is
formed in a center portion that corresponds to the location of the
second edge portion(s) 7b where the bending of the strip 6 and
vertical locking takes place. FIG. 25b shows that the first 7a and
the second 7b edge portions may be formed by removal of material in
the locking groove 14 only.
An advantage is that only one jumping tool or rotating carving tool
is needed at one short edge in order to form the first and second
section. In the embodiment in FIG. 25c the flex groove 39 is at
least partly open towards one edge side and only has one wall in a
direction along the edge so that it is located in a peripheral
portion of the edge in the length direction thereof.
Generally, it is noted that each wall of the flex groove may be
vertical or, alternatively, have a transition region so that a
depth of the flex groove increases along the edge from a minimal
depth to a maximal depth.
Moreover, there may be two or more flex grooves 39 arranged along
the edge. In the embodiment in FIG. 25d there are two flex grooves
39 which are at least partly open towards a respective side edge,
each having one wall in a direction along the edge, and located in
opposite peripheral portions of the edge in the length direction
thereof.
Preferably, the flex groove 39 does not extend entirely through the
second panel 1'.
By way of example, the flex groove 39 may have a vertical extension
between 30% and 60% of a maximal thickness of the panel, e.g. 40%
or 50%.
As shown in the top views of the first panel 1 in FIGS. 26a-26b,
one or a plurality of slits 49 may be formed in the strip 6 along
the edge of the first panel 1 in order to increase the flexibility
of the strip while still maintaining sufficient locking strength. A
cross-sectional shape of the slit 49 may be rectangular, square,
circular, oval, triangular, polygon shaped, etc. Preferably, the
shapes of the slits 49 are the same along the edge, but varying
shapes are also conceivable. The slits may be formed in a cost
efficient way with a rotating punching tool. The slits 49 may be
provided in all embodiments described in the disclosure. Such slits
and the previously described flex grooves 39 may be combined in all
embodiments of the disclosure.
The first panel 1 may have a slit 49 and the second panel may have
a flex groove 39. The slits 49 are preferably provided inwardly of
the locking element 8.
Preferably, the slits 49 extend entirely through the strip 6 to the
rear side 60.
Alternatively, however, the slits 49 may not extend through the
strip. The slits may have a vertical extension between 30% and 60%
of a minimal thickness of the strip.
The slits may be provided in the upper strip surface 6a. In the
embodiment in FIGS. 24a-24d the slits 49 may be provided in a strip
surface 66 connecting the side wall 45 and the second locking
element 8' or in a strip surface 67 connecting the first locking
element 8 and the second locking element 8'. Alternatively, or
additionally, the slits may be provided in the rear side 60 of the
first panel 1.
In the embodiment in FIG. 26b, the slit 49 is open towards one edge
side and has only one wall in a direction along the edge. Such slit
offers the advantage that the second section 7b may be used as a
start section. The slit 49 will increase the flexibility of the
strip and separation forces will be lower during the initial stage
of the locking until the first edge section 7a becomes active. A
similar slit 49 may be formed in the opposite side edge.
Generally, it is noted that each wall of the slits may be vertical,
i.e. parallel with a direction perpendicular to the horizontal
plane. For example, in the embodiment in FIG. 26b wherein the slits
49 have a circular shape, the inner surface of the slit 49 may be
cylindrical. Alternatively, however, the wall may have a transition
region so that a depth of the slit increases from a minimal depth
to a maximal depth. For example, in the embodiment in FIG. 26b, the
inner surface of the slit 49 may be frustoconical.
FIGS. 27a-27c show an embodiment comprising a flexible locking
element 8 that may be bended and/or compressed inwardly during
locking. The flexible locking element 8 is provided at an outer
part of the strip 6 and is configured to engage with the locking
groove 14. An outer, lower part of the locking element 8 engages
with a locking surface 11b of the second panel 1' in the second
edge section 7b.
Moreover, an outer part of the locking element 8 is free with
respect to the locking surface 11b in the first edge section 7a.
Alternative embodiments of the locking surfaces have been described
above in relation to other embodiments of the disclosure wherein
reference is made thereto. In particular, the outer part of the
locking element 8 may be constant along the first edge and the
locking surface 11b may be shortened in the first edge sections 7a,
cf. the embodiment in FIG. 7a-7b.
Optionally, the flexible locking element may also be bended upwards
and/or downwards during locking.
Such embodiments may be used in floor panels with flexible core
materials, for example a core comprising thermosetting plastic
material, but may also be used in other applications. As already
noted, the locking system may be formed according to any previous
embodiment of the disclosure. A horizontal extension of the locking
element 8 may be larger than a horizontal extension of the upper
surface of the strip 6a. Outer parts of the locking element 8 may
have a smaller vertical extension than inner parts of the locking
element for increasing the flexibility of the locking element.
The major difference as compared to the embodiments disclosed above
is that no space S is needed since the locking element 8 may be
bended upwards and/or compressed inwardly as shown in FIG. 27b. The
first 7a, 7a' and the second edge sections 7b may be formed with a
simple removal of material located at the outer part of the locking
element 8, as shown in FIG. 27c, or at the inner part of the
locking groove 14 (not shown).
The first edge section 7a' in FIG. 27c is optional and may be
replaced by a second edge section 7b. In other words, the second
edge section 7b may extend all the way to one side edge of the
first panel 1.
* * * * *